FWIW, we found "Dark Sky Discovery" to be a bit of a damp squib as they 'big up' some not so good locations while ignoring better ones. No matter where you are in UK, you're going to suffer with (or in some cases benefit from) light pollution (LP) -- nowhere in UK has truly dark skies, as you can see from the light pollution map I've linked below. So you need to figure out the magnitude of your objects of interest and then find somewhere where the LP is low enough to allow you to see them. Note that above, I said that in some cases you can benefit from a little light pollution? This is because in truly dark skies, the star field is flooded with higher magnitude (less bright) objects and it can be quite difficult to pick out the objects you actually want to observe. For example, if you're interested in the major planets (esp. Mars, Saturn and Jupiter) or the Moon a little LP isn't a bad thing because those objects are so much brighter than most of the other celestial objects. If you don't already know about them, two websites where you can get a lot of useful info are Stargazers Lounge and GoStargazing.co.uk -- the latter also gives details of public star parties and club meetings. Now to that LP map:
Clicky Link
FWIW, we too suffer from your frustration. Our favourite dark sky locations in Cornwall now have height barriers that the council installed during lockdown and there is nowhere local now to take our van (our mobile observatory) to deploy our 6" Newtonian and goto EQ mount, and that OTA has thus sat unused in its box for almost four years